The broad aims of the project are to determine the structure and mechanism of action of metalloenzymes. A variety of NMR probes for Zn(II) metalloenzyes have been developed and include 113Cd NMR on the Cd(II) substituted derivatives to explore the environment of the central metal ion, 13C NMR of gamma-13C-histidyl residues after incorporation into the bacterial enzyme,alkaline phosphatase to explore ligand interactions, 13C NMR of chemically modifed side chains (carboxymethylated carbonic anhydrase), 31P NMR of the phosphointermediates formed by a alkaline phosphatase, and 19FNMR of fluorotyrosyl labeled alkaline phosphatase. Kinetic studies of 32P-phosphate labeling of alkaline phosphatase are being carried out to determine the roles of the various metal ions (catalytic and structural) in the phosphorylation-dephosphorylation steps. Collaborative work is proceeding on the crystal structure of alkaline phosphatase which has now progressed to 4A resolution with very high quality electron density maps. The rule of Zn(II) in the transcription of DNA by T7 RNA polymerase is being investigated.